| 1 | /* |
| 2 | * Process-global memory barriers |
| 3 | * |
| 4 | * Copyright (c) 2018 Red Hat, Inc. |
| 5 | * |
| 6 | * Author: Paolo Bonzini <pbonzini@redhat.com> |
| 7 | */ |
| 8 | |
| 9 | #ifndef QEMU_SYS_MEMBARRIER_H |
| 10 | #define QEMU_SYS_MEMBARRIER_H |
| 11 | |
| 12 | #ifdef CONFIG_MEMBARRIER |
| 13 | /* Only block reordering at the compiler level in the performance-critical |
| 14 | * side. The slow side forces processor-level ordering on all other cores |
| 15 | * through a system call. |
| 16 | */ |
| 17 | void smp_mb_global_init(void); |
| 18 | void smp_mb_global(void); |
| 19 | #define smp_mb_placeholder() barrier() |
| 20 | #else |
| 21 | /* Keep it simple, execute a real memory barrier on both sides. */ |
| 22 | static inline void smp_mb_global_init(void) {} |
| 23 | #define smp_mb_global() smp_mb() |
| 24 | #define smp_mb_placeholder() smp_mb() |
| 25 | #endif |
| 26 | |
| 27 | #endif |